Improved eoofing compound



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GEORGE 0. SMITH AND J. H. SMITH, OF CHICAGO. ILLINOIS.

Letters Patent No. 70,478, dated November 5, 1867. I

IMPROVED ROOFING COMPOUND.

TO ALL'WHOM IT MAY CONCERN:

Be it known that we, GEORGE 0. SMITH and J. H. SMITH, of Chicago, in thecounty oi' Cook, and State of Illinois, have invented a new RoofingCompound; and we do hereby declare that the following is a full, clear,and exact description of the same, reference being bad to the sampleingredients accompanying this specification, in which No. 1 is sand andgravel; No. 2, common coal tar; No. 3, ground limestone; No. 4, groundcoke.

The object of our invention is to provide a roofing compound which canbe successfully applied to common sheeting, and make a cheap and durableroof without the use of felt onpapcr-cloth'; and its nature differsessentially from any roofing material, in the fact that coke is employedas the most solid absorbent of coal tar of any material convenient foruse, considering its cost, and as it is comparatively indestructible,agreat advantage is gained, not only in solidity, but in the durabilityof the roof when put on second, the use of ground limestone is lmportantin filling the pores or spaces between the gravel and'sand, and, whenused in combination with the other ingredients, hereinafter described,forms a roof almost as hard as stone, and yet sufiiciently elastic toprevent cracking in cold weather.

In order to give a correct understanding of our invention, we willnowgive-the process in full.

We usually take two parts of grbund limestone, one partiground coke, andone part of sand and coal tar, and mix them together, after which thecompound is ready to spread on the sheeting; after which the roof shouldbe covered with as much sand or gravel as the composition will hold, andthe roof, after having time to get dry, will become hard and turn watersimilar to roots laid with felt and common composition. One thing shouldbe attended to, which is the jointing of the sheeting, so as to leavebut small opening between the planking, otherwise the composition may bewasted or the roof defective. A heavy coat of material should be used,and made of such consistency as will readily fill all of the cracks andjoints in the sheeting, whereby a roof may be made which is bothwater-tight and durable.

We are not particular as to the proportions of tar, sand, and groundlimestone used as a first coating, the object being to form a cement ofthe greatest strength, and of such consistency as can be readily spreadon sheeting or other covering, and not crack in cold weather her run inwarm.

Having thus described our roofing compound, what we-claim, and desire tosecure by Letters Patent, is-- A roofing, composed of the ingredientsherein named, substantially as set forth.

' GEO. 0. SMITH,

J. H. SMITH.

Witnesses:

GEO. -L. CHAPIN, A. HAYWARD.

